Apparatus and method for mining granular ore



March 1967 H. B. CANNON, SR, ETAL 3,311,414

APPARATUS AND METHOD FOR MINING GRANULAR ORE Filed April 9, 1964 5Sheets-Sheet 2 Down 5 broke mm. m s OSJ M H mm m WWW w B o 1 r P W y. I

M a u M K 2 g arch 28, 1967 H, CANNON, SR, ETAL 3,311,414

APPARATUS AND METHOD FOR MINING GRANULAR ORE Filed April 9, 1964 3Sheets-Sheet 3 INVENToRs United States Patent 3,311,414 APPARATUS ANDMETHOD FOR MINING GRANULAR ORE Harry B. Cannon, Sn, Harry B. Cannon,Jr., and Hugh N. Cannon, all of R0. Box 2432, Lakeland, Fla. 33802 FiledApr. 9, 1964, Ser. No. 359,552 12 Claims. (Cl. 29918) This applicationis a continuation-in-part of copending application Ser. No. 308,244,filed Sept. 11, 1963, and now abandoned.

This invention relates to an apparatus and method for the deep-wellmining of granular ore, and it more particular relates to such anapparatus and method for the mining of granular phosphate ore.

In existing methods for deep-well mining of granular ore such asphosphates, the ore is diluted in situ by jetting water into the matrixin an attempt to wash it into the suction of a pump loosely insertedthrough a well casing. Such methods suck cavities in the ore matrixwhich develop into efficient filter chambers that accept water from thesurrounding sands but prevent the ore from migrating to the well pipe.In such cavities the angle of ore repose reaches the vertical to causesmall diameter vertical shaft-like withdrawal and minimum ore productionper well.

An object of this invention is to provide a simple and efiicientapparatus and method for deep-well mining of granular ore.

In accordance with this invention, a positive displacement pump issealed to the lower end of a conduit well which is inserted down throughthe ground into the bed or matrix of granular ore. The lower end of theconduit is sealed Within the ground to cause the positive displacementpump to concentrate on drawing the granular ore in its undiluted naturalstate into the conduit and force it to the surface of the ground. Broadsubsidence of the matrix is therefore induced without caving. A footextension on the conduit below the pump supports it upon a basal shelfunder the matrix and above any layer of undesirable material upon it.Fluid may be added to the ore within the suctionchamber of the pump todilute it and therefore facilitate its movement to the surface.

In an advantageous form of this invention, a vertically reciprocatingtype of positive displacement pump is formed by a plunger insertedwithin the bottom of the conduit above a foot valve. A check valve inthe plunger opens upon downward movement of the plunger to force any orein the suction chamber above the foot valve up through the plunger intothe conduit where it is pushed by successive strokes up to the surface.Upward strokes close the check valve and suck ore through the foot valveto the suction chamber. Water is pumped into the suction chamber througha hollow plunger rod to dilute the granular ore and facilitate itsmovement to the surface. The water is controlled to be introducedprincipally on the downward stroke. The upper end of the conduit can beinsulated from subsidence of the ore strata and overburden by supportingit upon a barge floating upon a dammed pool of water, the surface ofwhich is maintained at a substantially constant level.

In accordance with another aspect of this invention a turbine pump isinserted in a conduit well which is sealed in the ground and extendsinto the bed of granular ore. As natural ore is drawn through holes inthe bottom of the conduit dilution water is applied to it in the conduitto facilitate its movement to the surface of .the ground by the actionof the turbine pump. The

3,3 l IA l4 Patented Mar. 28, i257 Novel features and advantages of thepresent invention will become apparent to one skilled in the art from areading of the following description in conjunction with theaccompanying drawings wherein similar reference characters refer tosimilar parts and in which:

FIGS. 1-2 are cross-sectional views in elevation of one embodiment ofthe invention showing different phases of operation;

FIGS. 3-4 are exploded cross-sectional views in elevation of a portionof the apparatus shown in FIG. 2 showing different phases of operation;

FIG. 5 is a cross-sectional view in elevation of an alternative form ofthe invention shown in FIGS. 1-4; and

FIG. 6 is a cross-sectional View in elevation of an alternative form ofthe invention shown in FIGS. 24.

In FIG. 1 is shown a barge 12 which is used for setting mining apparatus10 into a matrix or bed of granular ore 14. Barge 12, which floats inwater such as a dammed pool above the strata or overburden coveringmatrix 14, comprises a platform 15 mounted on a pair of parallel spacedpontoons 16. Drilling equip ment 18, such as a conventional cable toolor rotarytype rig, is mounted on barge 12 in a slot between pontoons 16and drills a hole from ground surface 2% to the base of the bed ofmatrix or granular ore 14. As the hole or deep well is dug, it is muddedto make its side walls temporarily self-supporting. The variouscomponents of miningapparatus 10 are then inserted into the hole frombarge 12. Well pipe or conduit 26 of mining apparatus 10 is of the samediameter as the predrilled hole and is thus sealed in the hole. Sincepipe or conduit 26 is of the same diameter as the hole, it can belowered through hard rock layers below the surface through a minimumsize hole inasmuch as it has no outside connections, protuberances orirregularities. Additionally, while well pipe 26 is being lowered to itsoperating position, it cleans caved solids from its path, thus obviatingthe necessity of an auxiliary casing.

Where no layer of limestone or cap rock covers the matrix, the deep wellis drilled by well pipe or conduit 26 itself without any predrilling byusing a conventional simultaneous-jet-jar drive with a cable tool rig orby pumping well pipe 26 into the ground through its own pumping actionwith the use of a cable tool rig.

After mining apparatus 10 is set, barge 12 moves away and mining barge22, constructed similarly to barge 12, then floats to the deep well.Pump drive 24 for the particular type of pump, such as a turbine orrotary pump 27 as shown in FIGS. 6 and 7 or a vertically reciprocatingjack pump 25 as shown in FIGS. 3 and 4, is mounted on barge 22 forremoving ore from matrix 14 to a recovery receptacle in barge 22. InFIG. 2 pump drive 24 is shown as a reciprocating mechanism for operatingjack pump 25, later described in detail. Since the lower end of miningapparatus 10 is sealed within the ore bed, only the ore migrates to itand since the ore or matrix supporting the strata is removed over alarge area the strata above it gradually lowers as broad subsidence isinduced without any local caving as shown in FIG. 2. The matrix isremoved over a large area because this high density pumping withoutcaving stimulates extended subterranean flow at relatively flat slopesand produces a maximum tonnage of mined ore per well. Since barge 22floats, it maintains pump drive 24 at substantially a constant elevationthroughout the mining of ore 14 and thus insulates the upper end ofconduit 26 from the subsidence of the matrix and overburden. After thewell has been completely mined, mining barge 22 moves off and settingbarge 12 returns to recover the pumping equipment.

In FIGS. 3 and 4 is shown vertically reciprocating jack pump whichoperates in conduit 26. The base of well pipe or conduit 26 isperforated, providing an inlet 28 for the ore. Since the perforations inpipe 26 are below the limestone cap and pipe 26 extends above the groundsurface, the strata above ore 14 is not mined. Foot extension 29supports conduit 26 below pump 25 upon basal shelf 31 under matrix 14.Apertured .partition in the base of well pipe 26 separates intakechamber 32 exposed to ore 14 from suction chamber 34. Ball 36 of footvalve 41 floats in suction chamber 34 and upon the downward stroke ofplunger 38 is seated in aperture 35 to close foot valve 41 and thus sealchambers 32 and 34 from each other. Plunger or pump rod 38 reciprocatesin suction chamber 34 and carries a perforated flange or piston head 40which separates suction chamber 34 from outlet chamber 42. Floating discor valve head 44 of check valve 45 is seated upon perforated head 49when plunger 38 is in its upward stroke to seal chambers 34 and 42 fromeach other. Outlet 46 in outlet chamber 42 opens into a recoveryreceptacle (not shown) above the ground surface. A hose or tube 48 leadsfrom a source of water (not shown) under pressure and is connected toplunger 38, which is hollow, to provide a fluid passage for feedingwater into suction chamber 34. The fluid is intermittently supplied tosuction chamber 34 to dilute the ore in the suction chamber. Thecyclical control of fluid introduction is accomplished by a sleeve valve(not shown) which is attached to plunger 38 or by solenoid valve 50,later described in detail, to close the passage on the up stroke of theplunger and to open it on the down stroke. The cyclical waterintroduction increases the efiiciency of jack pump 25 which applies apositive suction pressure approaching the maximum of 30 feet.

When plunger 38 is moved in its upward or lift stroke, suction iscreated in suction chamber 34 to unseat foot valve ball 36 and to suckore 14 from intake chamber 32 into suction chamber 34. At the end of theupward stroke, actuating projection 54 hits switch 52 to open solenoidvalve 50. When plunger 38 is moved in its downward stroke, pressure isincreased in suction chamber 34 and decreased in outlet chamber 42 tounseat floating check valve head 44 and to seat foot valve ball 36.Since suction chamber 34 is sealed by foot valve 41, the water enteringthe suction chamber cannot escape to the bed of matrix 14 but dilutesthe ore in suction chamber 34 to create a slurry which is washed throughpiston head 40 and around check valve head 44 in outlet chamber 42. Atthe end of the downward stroke, actuating projection 55 hits switch 52to close valve 50. When plunger 38 is again moved upward, suction iscreated in chamber 34 to unseat foot valve ball 36 sucking more highdensity natural ore into chamber 34 and simultaneously, as pressure inchamber 42 is increased, pressure and the weight of the slurry ordiluted ore seats valve head 44 to close communication between suctionvalve 34 and outlet chamber 42. As the plunger continues to moveupwardly, the ore is forced from outlet 46 through successive strokesinto the recovery receptacle. By this continuous process, the ore issucked int-o conduit 26 in its natural undiluted state, is diluted inchamber 34 and is forced intermittently or pulsatingly to the surface.Since conduit 26 is sealed in, only matrix 14 migrates to conduit 26 andthe overlying strata gradually lowers or subsides over a broad areawithout producing any local cavities. A

In FIG. 5 is shown an alternative construction for well pipe or conduit26. In this form the conduit comprises a pair of inner and outer casings7t) and 72. Seal-ing material 74 fills the annular space betwen thecasings to provide a sealed-in deep well. This form of construction isuseful to protect inner pump casing 70 from being damaged by caved orsubsiding solids in the predril'led hole when casing 7 t) is insertedfor operation.

In the embodiment shown in FIG. 6 the ore is recovered through conduit26 by turbine pump 76. Conduit 26 is sealed in the well at its upper endand rests on basal shelf 31 by foot support 2%. Flange 92 mounts conduit26 to platform 7% above the ground. Turbine pump 76 includes a bowlassembly '78 consisting of an outer stator 80 and a plurality of rotorsor vanes 82 having bearings 92. Rotors 82 are driven by a hollow shaft84 from a drive mechanism (not shown) above the ground. Shaft 84 isenclosed in and protected by concentric tube 86 which together withcasing 88 forms a passage 89 for the ore to discharge it into therecovery receptacle through outlet 9%. Water is fed into conduit 26through tubular extension 96 to dilute the natural ore in the bottom ofconduit 26 and facilitate its movement through passage 89, while bypassline 98 joins extension 96 and the hollow interior of drive shaft 84 tolubricate bearings 92 through ports 100 at each bearing.

When the drive shaft 84 is rotated, turbine pump 76 sucks natural oreinto conduit 26 through openings 28 at the bottom of the conduit. Theentire bottom portion of conduit 28 thus forms a suction chamber. Theore in its natural state is diluted by water in this suction chamber andthe diluted ore is sucked into bowl assembly 78 through passage 39 anddischarged from outlet into the recovery receptacle. The dilution Wateris fed into conduit 26 at a slower rate than the slurry or diluted oreis pumped from conduit 26 to insure that Water will not escape throughopenings 28 and dilute the ore outside of conduit 26. Thus since thedilution is confined to conduit 26 the overlying strata gradually lowersor subsides over a broad area without producing any local cavities.Because tubular pump 76 is continuously sucking the ore into conduit 26and through bowl assembly 78, the slurry is non-intermittently orcontinuously discharged from outlet to substantially reduce the amountof time required to mine the granular ore.

What is claimed is:

1. An apparatus for mining granular ore through a well in the groundcomprising a conduit extending from above said ground into the bed ofgranular ore, the bottom of said conduit being sealed in said well, apositive displace ment pump being sealed to the bottom of said conduitwhich sucks ore into said conduit and pumps it above said ground wherebysaid undiluted ore bed is caused to continuously laterally flow andbroadly subside toward said pump without cavitation, said positivedisplacement pump comprising a plunger rod extending from above saidground to the lower end of said conduit, an inlet opening in the bottomof said conduit, a foot valve in said conduit above said inlet openingto form a suction chamber below said plunger rod, a check valve in saidplunger for causing said ore to pass upwardly through said plunger andsaid conduit, said plunger rod being hollow, a source of water connectedto the upper end of said plunger rod, a reciprocating means connected tothe upper end of said plunger rod for causing said plunger rod to moveup and down whereby ore is successively sucked into said suction chamberand forced upwardly by said plunger rod through said conduit, an outletat the top of said conduit above said ground level, water control meansconnected to said hollow plunger rod for introducing water into saidsuction chamber principally upon downward movement of said plunger rod,and the upper end of said conduit and said means for reciprocating saidplunger being supported upon a floating platform whereby they aremaintained at a substantially constant elevation as said ground surfacesubsides.

2. An apparatus for mining granular ore through a well in the groundcomprising a conduit extending from above said ground into the bed ofgranular ore, the bottom of said conduit being sealed in said well, apositive displacement pump being sealed to the bottom of said conduitwhich sucks ore into said conduit and pumps it above said ground wherebysaid undiluted ore bed is caused to continuously laterally flow andbroadly subside toward said pump without cavitation, said positivedisplacement pump comprisin a plunger rod extending from above saidgroud to the lower end of said conduit, an inlet opening in the bottomof said conduit, a foot valve in said conduit above said inlet openingto form a suction chamber below said plunger rod, a check valve in saidplunger for causing said ore to pass upwardly through said plunger andsaid conduit, said plunger rod being hollow, a source of water connectedto the upper end of said plunger rod, a reciprocating means connected tothe upper end of said plunger rod for causing said plunger rod to moveup and down whereby ore is successively sucked into said suction chamberand forced upwardly by said plunger rod through said conduit, an outletat the top of said conduit above said ground level, water control meansconnected to said hollow plunger rod for introducing water into saidsuction chamber principally upon downward movement of said plunger rod,said water control means comprising a solenoid valve connected to saidsource of water, a pair of spaced actuating projections on said plungerrod and switch means on said conduit connected to said solenoid valve,one of said actuating projections being disposed to contact said switchmeans at the end of the upward stroke of said plunger rod to open saidsolenoid valve, and the other of said actuating projections beingdisposed to contact said switch means at the end of the downward strokeof said plunger to close said solenoid valve whereby water is introducedinto said suction chamber only upon said downward stroke of said plungerrod.

3. An apparatus for mining granular ore through a well in the groundcomprising a conduit extending from above said ground into the bed ofgranular ore, said conduit being sealed in said well, an inlet openingin the bottom of said conduit for permitting said granular ore to entersaid conduit, water feeding means for diluting said ore in said conduitand allowing the ore in said bed outside of said conduit to remainundiluted, a pump in said conduit above said inlet opening for suckingundiluted ore into said conduit and pumping ore above said groundwhereby said undiluted ore is caused to continuously laterally flow andbroadly subside toward said pump without cavitation, said pump being aturbine pump, said turbine pump having a drive shaft, a hollow casingcommunicating with said turbine pump and being mounted concentricallyaround said drive shaft to provide a discharge passage for said ore, anoutlet in the upper portion of said conduit communicating with saidpassage for discharging said ore therefrom, an inner casing beingmounted about said drive shaft to shield said drive shaft from the orein said passage, and said inner casing being disposed within and spacedfrom said hollow casing whereby the space between said casings comprisessaid ore discharge passage.

4. An apparatus for mining granular ore through a well in the groundcomprising a conduit extending from above said ground into the bed ofgranular ore, said conduit being sealed in said well, an inlet openingin the bottom of said conduit for permitting said granular ore to entersaid conduit, water feeding means for diluting said ore in said conduitand allowing the ore in said bed outside of said conduit to remainundiluted, a pump in said conduit above said inlet opening for suckingundiluted ore into said conduit and pumping ore above said groundwhereby said undiluted ore is caused to continuously laterally flow andbroadly subside toward said pump without cavitation, said pump being aturbine pump, said turbine pump having a drive shaft, a hollow casingcommunicating with said turbine pump and being mounted concentricallyaround said drive shaft to provide a dis charge passage for said ore, anoutlet in the upper portion of said conduit communicating with saidpassage for discharging said ore therefrom, said drive shaft beinghollow, bearing means being disposed around said shaft and communicatingwith its hollow interior, and said water feeding means leading to saidhollow interior to provide a continuous passage for lubricating saidbearing means.

5. A method of mining granular ore comprising the steps of drilling ahole from the ground surface into a bed of said granular ore through alayer of water impervious strata, inserting a conduit in said hole,sealing a portion of said conduit in said layer of strata, inducing theore to broadly laterally subside without cavitation by applying suctionat the bottom of said conduit to the undiluted ore to cause it to flowinto the bottom of said conduit and by preventing dilution of the oreoutside the conduit, and pumping the ore upwardly through said conduit.

6. A method as set forth in claim 5 wherein water is mixed with said orewithin said conduit to dilute the ore in said conduit and facilitate itsmovement to the surface.

7. A method as set forth in claim 5 wherein said conduit is sealedwithin said hole by mudding it before inserting said conduit to cause itto stand up temporarily and thus seal about said conduit after it isinserted.

8. A method as set forth in claim 5 wherein said steps of drilling saidhole and inserting and sealing said conduit within it are donesimultaneously by pumping said conduit into the ground.

9. A method as set forth in claim 5 wherein the upper end of saidconduit is supported upon a floating platform, said floating platformbeing floated upon the surface of a pool of water, and the surface ofsaid platform being maintained at a substantially constant elevation toaccordingly maintain said upper end of said conduit at a substantiallyconstant elevation as said ground subsides as said ore is pumped fromunder it.

10. A method as set forth in claim 5 wherein a positive displacementpump is inserted within said conduit and said step of pumping isintermittent by means of said positive displacement pump.

11. A method as set forth in claim 5 wherein a turbine pump is insertedwithin said conduit, and said step of pumping is continuous andnon-intermittent by means of said turbine pump.

12. A method as set forth in claim 11 wherein water is fed into saidconduit at a slower rate than said ore is pumped from said conduitwhereby the ore outside of said conduit is not diluted by said water.

References Cited by the Examiner UNITED STATES PATENTS 278,751 6/1883Shaw 166-105 298,443 5/ 1884 Brotherhood 299--9 552,856 1/1896 Roach-324 X 740,731 10/ 1903 Beatey 2997 834,384 10/1906 Johnston 103-1191,389,007 8/1921 Norbye 166-105 1,703,354 2/ 1929 Nevill 1 03-2042,255,167 9/1941 Hunn 37-57 2,405,697 8/ 1946 Houston et al 103-204ERNEST R. PURSER, Primary Examiner.

CHARLES E. OCONNELL, Examiner.

5. A METHOD OF MINING GRANULAR ORE COMPRISING THE STEPS OF DRILLING AHOLE FROM THE GROUND SURFACE INTO A BED OF SAID GRANULAR ORE THROUGH ALAYER OF WATER IMPERVIOUS STRATA, INSERTING A CONDUIT IN SAID HOLE,SEALING A PORTION OF SAID CONDUIT IN SAID LAYER OF STRATA, INDUCING THEORE TO BROADLY LATERALLY SUBSIDE WITHOUT CAVITATION BY APPLYING SUCTIONAT THE BOTTOM OF SAID CONDUIT TO THE UNDILUTED ORE TO CAUSE IT TO FLOWINTO THE BOTTOM OF SAID CONDUIT AND BY PREVENTING DILUTION OF THE OREOUTSIDE THE CONDUIT, AND PUMPING THE ORE UPWARDLY THROUGH SAID CONDUIT.